/*
 * 11/19/04 1.0 moved to LGPL.
 * 12/12/99 Initial implementation.		mdm@techie.com. 
 *-----------------------------------------------------------------------
 *   This program is free software; you can redistribute it and/or modify
 *   it under the terms of the GNU Library General Public License as published
 *   by the Free Software Foundation; either version 2 of the License, or
 *   (at your option) any later version.
 *
 *   This program is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *   GNU Library General Public License for more details.
 *
 *   You should have received a copy of the GNU Library General Public
 *   License along with this program; if not, write to the Free Software
 *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 *----------------------------------------------------------------------
 */

package javazoom.jl.decoder;

/**
 * A Type-safe representation of the the supported output channel constants.
 * 
 * This class is immutable and, hence, is thread safe.
 * 
 * @author Mat McGowan 12/12/99
 * @since 0.0.7
 */
public class OutputChannels {
	/**
	 * Flag to indicate output should include both channels.
	 */
	public static final int BOTH_CHANNELS = 0;

	/**
	 * Flag to indicate output should include the left channel only.
	 */
	public static final int LEFT_CHANNEL = 1;

	/**
	 * Flag to indicate output should include the right channel only.
	 */
	public static final int RIGHT_CHANNEL = 2;

	/**
	 * Flag to indicate output is mono.
	 */
	public static final int DOWNMIX_CHANNELS = 3;

	public static final OutputChannels LEFT = new OutputChannels(LEFT_CHANNEL);
	public static final OutputChannels RIGHT = new OutputChannels(RIGHT_CHANNEL);
	public static final OutputChannels BOTH = new OutputChannels(BOTH_CHANNELS);
	public static final OutputChannels DOWNMIX = new OutputChannels(DOWNMIX_CHANNELS);

	private /* final */ int outputChannels;

	/**
	 * Creates an <code>OutputChannels</code> instance corresponding to the given
	 * channel code.
	 * 
	 * @param code one of the OutputChannels channel code constants.
	 * 
	 * @throws IllegalArgumentException if code is not a valid channel code.
	 */
	public static OutputChannels fromInt(int code) {
		switch (code) {
		case LEFT_CHANNEL:
			return LEFT;
		case RIGHT_CHANNEL:
			return RIGHT;
		case BOTH_CHANNELS:
			return BOTH;
		case DOWNMIX_CHANNELS:
			return DOWNMIX;
		default:
			throw new IllegalArgumentException("Invalid channel code: " + code);
		}
	}

	private OutputChannels(int channels) {
		outputChannels = channels;

		if (channels < 0 || channels > 3)
			throw new IllegalArgumentException("channels");
	}

	/**
	 * Retrieves the code representing the desired output channels. Will be one of
	 * LEFT_CHANNEL, RIGHT_CHANNEL, BOTH_CHANNELS or DOWNMIX_CHANNELS.
	 * 
	 * @return the channel code represented by this instance.
	 */
	public int getChannelsOutputCode() {
		return outputChannels;
	}

	/**
	 * Retrieves the number of output channels represented by this channel output
	 * type.
	 * 
	 * @return The number of output channels for this channel output type. This will
	 *         be 2 for BOTH_CHANNELS only, and 1 for all other types.
	 */
	public int getChannelCount() {
		int count = (outputChannels == BOTH_CHANNELS) ? 2 : 1;
		return count;
	}

	public boolean equals(Object o) {
		boolean equals = false;

		if (o instanceof OutputChannels) {
			OutputChannels oc = (OutputChannels) o;
			equals = (oc.outputChannels == outputChannels);
		}

		return equals;
	}

	public int hashCode() {
		return outputChannels;
	}

}
